I don't suppose you have an NT administrator there do you?
To me it appears that for some reason NT can not write to the control file, this is a bad thing. Is it shutting down the instance, it appears to be.

My spidey sense tells me that you should make sure you have valid copies of your control files (and all critical files)ASAP, something about these errors scares me. I hope I am mistaken.

Did you tkprof the trace file listed?

MH